Organo-calcium compounds



United States Patent 29,92 8 Claims. (Cl. 260-612) This is a division ofapplication Serial No. 69,843, filed November 17, 1960, and now PatentNo. 3,163,630.

The present invention relates to the polymerization of conjugateddiolefines by means of catalysts, comprising organo-calcium compounds,as well as to new organocalcium compounds which are suitable ascatalysts for the polymerization of olefinically unsaturated monomers.

The use of alkali metals or alkaline earth metals as catalysts for thepolymerization of conjugated diolefines, for example those of thebutadiene series, has long been known. The polymerization of conjugateddiolefines with such metallic catalysts does, however, presentconsiderable technical processing difliculties, which are causedprimarily by long and different periods of latency and also by the factthat the polymerization often starts violently and the progress thereofis diflicult to control. Consequently, this process has onlyoccasionally been able to acquire a certain degree of importance, forexample, for the production of polybutadiene with sodium or a sodium/potassium alloy.

It has also already been proposed to use organometallic compounds aspolymerization catalysts. For example, German Patent No. 255,786describes the polymerization of conjugated diolefines to rubber-likesubstances by means of organometallic compounds of the alkali metals andalkaline earth metals, special complex compounds of sodium alkyls andzinc dialkyls being disclosed. The process of this patent specificationalso does not provide a solution which can be exploited industrially.This is inter alia attributed to the fact that the physical and alsotechnological properties of the polymers, thereby obtained, did notsatisfy the standards which are required of elastomers which are usedindustrially.

It is furthermore known that the physical and technological propertiesof polymeric diolefines are substantially influenced by the structure ofthese polymers. Particularly valuable properties are shown by thosepolymers which comprise a homogeneous or at least substantially regularstructure. One example of this type which has long been known isprovided by natural rubber, the most important constituent of which issubstantially uniform 1,4-cis-poly-2-methyl butadiene. Because of itsstructural features, natural rubber combines such a number of valuablephysical and technological properties that even today it is still ofoutstanding technical importance.

Practically all known metallic and organometallic catalysts causediolefines to polymerize to polymers with a more or less irregularstructure, which is of no particular industrial interest. It is knownthat catalysts based on lithium or organic lithium compounds lead topolymers with substantially homogeneous structure, under certainconditions, when polymerizing diolefines, more especially 2-methylbutadiene. Nevertheless, the technical processing difficulties, whichalready have been mentioned above, arise when metallic lithium is usedas catalyst. A further obstacle is the high reactivity of lithium withrespect to nitrogen, which necessitates working in an inert gasatmosphere. Organic lithium compounds certainly show an appreciablybetter behaviour in this respect, but generally yield polymers ofconsiderably lower molecular weights, which cannot be considered for usein rubber industry. In order to obtain polymers of a sufficiently highmolecular weight and thus also adequate physical and technologicalproperties, the concentration of the catalytically active organiclithium compound must be kept extremely low. However, this on the otherhand sets very high standards as regards the degree of purity of themonomeric olefines, and these can only be satistied at considerableexpense. Furthermore, in view of the very small quantities of catalyst,traces of foreign substances, such as air, moisture and the like, leadto considerable disturbances in the polymerization reaction.

It has now been found that conjugated diolefines, especially those ofthe butadiene series, can be polymerized without any of theaforementioned difiiculties to provide products of high molecularweight, by using catalysts which contain an organic calcium compound asessential constituent. It is possible in this way to obtain polymerswhich are of high molecular weight and show a substantially uniformstructure, more especially as regards their steric structure and asregards branchings, for example when Z-methyl-butadiene is used asmonomer. This discovery was surprising as the organometallic compoundsof other alkaline earth metals, for example of zinc or magnesium, haveonly a low catalytic efficacy and only produce a poor yield of polymersof low molecular weights. In contrast thereto, the polymerization isachieved in a few hours with practically quantitative yields, even atroom temperature, when using catalysts based on organic calciumcompounds. A particular advantage of the catalysts according to theinvention, compared with the organic lithium compounds, is that theyhave a substantially lesser regulating action and consequently yieldpolymers of high molecular weight also with higher catalystconcentrations.

It has also been found that not only conjugated diolefines, but alsoother vinyl compounds, can be polymerized with the catalysts accordingto the invention, by themselves or admixed with one another and also inadmixture with conjugated diolefines.

Cataly-tically active compounds in accordance with the present inventionare quite generally organic calcium compounds with at least onecalcium-carbon bond, more especially those which conform to the generalFormula I In this formula R and R each can represent alkyl having 1 to20 carbon atoms, cycloalkyl, aralkyl or aryl radicals. Furthermore, theradicals R and R can be like or different and they can also carry heteroatoms, advantageous- :ly oxygen, nitrogen or halogen atoms, in the formof substituents, or oxygen or nitrogen atoms in the form of chain orring members.

The following are examples of representatives of this type of compound:calcium diphenyl, calcium phenyl butyl, calcium phenyl ethyl, calciumphenyl propyl, calcium phenyl isobutyl, calcium phenyl strearyl, calciumdibenzyl, calcium phenyl cyclohexyl, calcium phenyl-2-ethyl propyl,calcium butyl-(2-N,N'-diInethylamino-ethyl) and calcium phenyl ally-l.

For the preparation of such organic calcium compounds, the knownreaction of suitable organometallic compounds with calcium can be used.For example, calcium diethyl and calcium diphenyl, respectively, can beprepared from zinc diethyl or mercury phenyl and metallic calcium in aninert solvent.

However, it is preferred to use a new type of calcium compounds whichare obtained by reacting organic calcium halides of the general formulawith organic alkali metal compounds of the general formula:

(III) n 2 In these formulae, R and R each represent an aliphatic radicalhaving 1 to 20 carbon atoms, cycloaliphatic, araliphatic or aromaticradicals. The radicals R and R can in this case also be like ordifferent and they can carry hetero atoms, preferably oxygen, nitrogenor halogen atoms in the form of substituents, or oxygen or nitrogenatoms in the form of chain or ring members. Furthermore, X represents ahalogen atom such as chlorine, bromine, or iodine, preferably bromine oriodine, and Me represents an alkali metal, such as lithium, sodium orpotassium, preferably lithium, and It stands for a whole integer of 1 to4.

Contrary to experience met in reactions with analogou components, thereis no deposition of metal halides in this case. Rather are thereobtained compounds of obviously complex nature which in many cases havesubstantially better solubility in organic solvents (such as ethers andaromatic hydrocarbons), than the starting products.

It has also been found that the preparation of the new 7 organic calciumcompounds can be carried out, in the presence of additional alkali metalor alkaline earth metal halides, without the solubility of the organiccalcium compounds in solvents such as ethers or aromatic hydrocarbonsbeing appreciably reduced thereby. On the contrary, it is even possibleconsiderably to improve the solubility of the organic calcium compoundby such an addition of an alkali metal or alkaline earth metal halide.In contrast thereto, it was to be expected that the presence of alkalimetal or alkaline earth metal halides would have a salting-out elfect onthe basis of the solubility product.

The organic calcium compounds to be prepared according to the inventionare not simple mixtures, but are new complex compounds of definedcomposition, the properties of which differ considerably from those ofthe initial substances. For example, it is not possible for lithiumbutyl to be separated out from the compound by washing or extraction bymeans of an aliphatic or cycloaliphatic hydrocarbon. Similarly, it isnot possible to split up the complexes into their starting components byfractional precipitation or by recrystallization from inert solvents.

The organic calcium halides of the composition are obtained in a mannercorresponding to the Grignard compounds of similar structure frommetallic calcium and halogenated hydrocarbons. Suitable organic calciumhalides are for example calcium phenyl iodide, calcium tolyl bromide,calcium naphthyl iodide, calcium methyl iodide, calcium ethyl bromide,calcium propyl iodide, calcium butyl bromide, calcium stearyl iodide andcalcium cyclohexyl bromide.

'Suitable organic alkali metal compounds of the formula (Me) R are byway of example: sodium amyl, sodium phenyl, potassium phenyl, lithiummethyl, lithium ethyl, lithium butyl, lithium dodecyl, lithium stearyl,lithium cyclohexyl, lithium phenyl, lithium tolyl, lithium, o-methoxyphenyl, lithium'chlorophenyl, tetramethylene dilithium, hexamethylenedilithium, 1,5-dilithiumnaphthalene, 1,2- dilithium diphenyl propane,1,3,5-trilithium pentane, 1,3- S-trilithium benzene, phenyl isopropylpotassium etc. It is also possible to use the addition products ofalkali metals such as sodium and lithium with polynuclear aromatichydrocarbons such as naphthalene, anthracene.

Suitable alkali metal or alkaline earth metal halides, in the presenceof which the said organic calcium compound can be prepared, are forexample the chlorides, bromide or iodides of lithium, sodium, potassium,calcium etc.

The reactions for producing said new calcium compounds are generallycarried out in inert solvents such as aliphatic, aromatic,cycloaliphatic or araliphatic hydrocarbons, for example hexane, heptane,petroleum ether, parafiin oil, hydrogenated diesel oil, hydrocarbons ofthe Fischer-Tropsch synthesis, cyclohexane, methyl cyclohexane, benzene,toluene, xylene, methyl naphthalene and others. Furthermore the reactionmay be carried through in the presence of aliphatic, aromatic,cycloaliphatic and araliphatic simple or mixed ethers, such as diethylether, dibutyl ether, methyl butyl ether, phenylmethyl ether, diphenylether, cyclohexylmethyl ether, cyclic ethers such as dioxane,tetrahydrofurane, N-methyl morpholine; tertiary amines such as triethylamine, endoethylene piperazine or N-methyl piperidine, these additionalcompounds being preferably employed in amounts of 1-5 moles per,

atom of calcium present in the complex compound. An-

other suitable additional compound is triphenyl phosphine which may beemployed in amounts of 1-3 moles per atom of calcium. These additionalcompounds may enhance the activity of the present catalysts.

The solvents should be freed from those impurities which preferentiallyreact in foreseeable manner with the organometallic compounds of thetype described and thus lead to undesired or disturbing reactionproducts, that is to say, the organic calcium compounds according to theinvention show a particularly high reactivity, advantageously withrespect to those compounds which contain active hydrogen atoms, such aswater, acids, bases, alcohols, phenols, acetylenes, etc. Such compoundsshould consequently be absent during production and storage.

The organic calcium compounds according to the pres ent process can beproduced within a wide temperature range, this being substantiallydetermined by the reac-.

tivity of the starting components and also their other properties, suchas melting point, etc. Many of the reactions can be conducted at roomtemperature, but it is also possible to work at substantially lower orhigher temperatures, such as from -70 C. to C. It can in many cases beadvantageous to initiate the reaction at lower temperature and tocomplete it at higher temperature.

The proportions of the two components, i.e. organic cal-, cium halide(H) and organ-ometallic compound (III) to be used in the present processare advantageously in the order of magnitude of equivalent quantities,(that is to say the alkaline metal compounds should be employed in suchamounts that one alkaline atom is present per one halogen atom of thecalcium compound), but thisdoes not exclude the use of excesses of oneor other of the components in certain cases. The alkali metal oralkaline earth metal halides which sometimes are additionally presentcan comprise quantities of 0.1 to 10 mols, preferably 0.5 to 3 mols permol of organic calcium com pound.

The aforementioned catalysts may be characterized by the followinggeneral formula:

in which Me, R R X and n have the same meaning as above, the radial Rhaving a valency of 11.

Of special interest are compounds of the above formula in which Me islithium, n is 1, R is aryl, R is alkyl and X is bromine or iodine.

The catalysts which are prepared in the presence of alkali metal oralkaline earth metal halides correspond to the following generalformula:

in which Me, R R X, n have the same meaning as above, A stands for analkali or an alkaline earth metal halide, preferably lithiumchloride,l-ithiumbromide, lithiumiodide, calcium chloride, calcium bromide,calcium iodide and m stands for an integer preferably from 0.5 to 3.

For the preparation of the organic calcium halides under considerationas starting materials, the necessary calcium is preferably used infinely divided form, it being suitable for the reactivity to be furtherimproved by a suitable pretreatment such as initial corrosion withacids, iodine. Finely divided calcium alloys, for example those ofcalcium and magnesium, calcium and mercury, calcium and lithium, calciumand sodium can also be employed.

It is advantageous to stir vigorously during the reactions that is tosay, both in the preparation of the starting material and also of theorganic calcium compounds, especially when solid substances, such asmetallic calcium, sodium phenyl, lithium phenyl or others participate inthe reaction. Highspeed stirrers and intensive stirrers with acomminuting action (for example of the Ultra Turrax type) have provedespecially suitable. The reaction is furthermore preferably allowed totake place in an inert atmosphere, such as an atmosphere of nitrogen,helium, argon.

By choice and variation of the individual components, such as the alkalimetals, the hydrocarbon radicals and the halogens, as well as additionalalkali or alkaline earth metal halides, it is readily possible to varywithin wide limits the properties of the organic calcium compoundsaccording to the invention, particularly the solubility and reactivitythereof. Thus, it is possible on the one hand to prepare organic calciumcompounds which are substantially similar to the organic alkali metalcompounds as regards their reactive behaviour, but on the other hand itis also possible to obtain organic calcium compounds of the typedescribed which correspond in their behaviour entirely to theorganometallic compounds of the second group of the periodic system.

Other active catalyst systems consist of combinations of the aboverecited organic calcium compounds which, if necessary and as alreadyexplained, can also contain alkali halides, with those substances whichhave a very large surface. Such substances and the use thereof for theproduction of catalyst systems are for example described in US. patentapplication Serial No. 27,988, filed May 10, 1960, now US. 3,072,621,and Serial No. 27,486, filed May 9, 1960, now US. 3,149,099.

Mentioned by Way of example in this connection are: substances presentin finely divided form, that is to say, in the form of powder or dust orany other highly dispersed form, such as the metals magnesium, zinc,aluminum, iron, and-also metal oxides, such as magensium oxide, clciumoxide, zinc oxide, aluminum oxide, silicon dioxide, titanium dioxide,tin dioxide, zirconium dioxide, molybdenum oxide, iron oxide as well assilicates, graphite, polyvalent metal halides, such as magnesiumbromide, calcium chloride, titanium-(III)-chloride, zirconium-(IV)-chloride, tin-(II)-chloride, antimony-(lII)-chloride, iron-(HI)-bromide, chromium-(IID-chloride, nickel-(II)-bromide. By graphite,within the terms of the present invention, are understood for-ms ofcarbon which are more fully described in A. F. Holleman and E. Wiberg:Lehrbuch der anorganischen Chemie, 34-36th edition, Berlin, 1955, pages296-298. As examples, there are mentioned wood charcoal, animalcharcoal, blood charcoal, sugar charcoal, gas soot, lamp black, furnaceblack, flue black, acetylene soot, naphthalene soot, retort graphite,natural graphite. Catalysts of this type can be very satisfactorilydispersed in hydrocarbons, cause a very uniformly progressingpolymerization and have, in a Wide range of concentration, practicallyno regulating influence on the molecular weight of the polymers.

The various catalysts are especially suitable for polymerizinghydrocarbons of the butadiene series and their derivatives. Conjugateddiolefines of this type are for example butadiene, l-methyl butadiene,2-methyl butadiene-1,3, 2,3-dimethyl butadiene-11,3, 2-ethyl butadiene-1,3,2-phenyl butadiene-1,3, and 2-chlorobutadiene. It is obvious thatalso mixtures of these monomers, such as butadiene and 2-methylbutadiene, can be used for the polymerization. The present process hasproved excellently suitable for the polymerization of Z-methylbutadiene.

Suitable vinyl compounds which can be copolymerized with conjugateddiolefines, are aromatic vinyl substances, for example styrene orstyrenes which are alkylated in the nucleus or in the vinyl group, suchas alpha-methyl styrene, vinyl toluene, and also halogenated styrene,these vinyl compounds being preferably applied in amounts up to about 40percent, as calculated on the total weight of monomers applied.

The diolefines of the butadiene series to be used for the polymerizationshould merely be subjected beforehand to conventional known physical orchemical purifying processes, such as fractional distillation, heatingwith alkali metals in the presence of polymerization inhibitors andsubsequent distillation, treatment with organometallic compounds,aluminium oxide, silica gel and other active adsorbents or heavy metalsalts. Those compounds, which it can be foreseen would lead todeactivation of the catalyst system, should be substantially removed,especially compounds with active hydrogen atoms.

The catalyst concentration is advantageously so adjusted that about0.001 to 1.0 part by weight of calcium is present to 100 parts by weightof monomers. As regards catalysts which contain solid substances with alarge surface area, the ratio between calcium and the said largesurfacearea susbtances is substantially in the range from 1:10 to 1:5. Theproportions can however without disadvantage be above or below theselimits in cases where there are special requirements.

The polymerization is preferably conducted in the absence of atmosphericoxygen and moisture and in an inert atmosphere, such as nitrogen,helium, argon, hydrocarbon vapours and the like, and can be conducted asblock polymerization or solution polymerization.

Suitable solvents and diluents are saturated hydrocarbons, such aspropane, butane, .pentane, hexane as well as mixtures of suchhydrocarbons, such as petroleum ether, kerosene, diesel oil, parafiinoil, as well as cycloaliphatic hydrocarbons, such as cyclohexane, andaromatic hydrocarbons, such as benzene, toluene, xylene, can also beused for the same purpose.

When operating in accordance with the process of the invention, thepolymerization temperature is preferably not higher than C. andadvantageously is between 5 and +60 C. The pressure conditions are notcritical for the course of the polymerization. Atmospheric pressure canbe used, but it is also possible to work under reduced or elevatedpressures. The polymerization is advantageously allowed to proceed atpressures which result from the vapor pressures of the monomers andsolvents used and at the reaction temperatures employe-d.

The polymerization of conjugated diolefines with the aid of thecatalysts as described can be carried out intermittently orcontinuously. Suitable for intermittent opera tion are flasks,stirrer-type vessels and autoclaves, with which it is possible to workunder inert conditions. For continuous operation, a worm-vessel hasproved suitable, and it has also been found advisable to connect aninitial polymerization vessel before the worm in order to keep theresidence time in the actual worm element as short as possible.

The copolymerization of different diolefines, such asZ-methyl-butad-iene and butad1ene, can be readily carried out in thesame way.

On completion of the polymerization, the polymer is obtained as a solidmass where no solvent has been used and as a viscous solution in thecase where a solvent has been employed. By treatment with alcohols,acetone, alcohol/ water and acetone/ water mixtures, perhaps in thepresence of inorganic or organic acids, the polymer can be precipitated,the reactive organic calcium compounds being simultaneously deactivatedand removed. It can be advantageous during the working up to operate inthe presence of stabilizers and anti-oxidants, such as phenyl-[3-naphthylamine, N,N'-diphenyl-p-phenylene diamine,ditert.-butyl-p-cresol, di-tert.-butyl-hydroquinone,tris-(nonylphenyD-phosphite, in order to avoid anoxidation of thesensitive polymers and thus the premature degradation thereof. However,it is also possible for substances which deactivate the catalyst to beadded immediately after completing the polymerization, such as forexample organic acids, then to incorporate stabilizers and antioxidantsand to remove the solvent in a suitable apparatus, for example a kneaderor a Worm device. The drying of the stabiilzed polymerization productscan take place in air or in vacuum at normal or elevated temperatures.

In contrast to other known processes, no periods or only very shortperiods, of latency occur when using the catalysts according to theinvention. An additional advantage of the process described herein isthat the polymerization proceeds uniformly, even with relatively largebatches, and can be controlled without any particular expenditure fortechnical equipment. The polymers prepared by the present invention canbe of very high molecular weights, such as those otherwise only obtainedwith catalysts which, like metallic lithium, are very difllcult tocontrol during the process. It is readily possible in accordance withthe process to obtain polymers with a limit viscosity of [1 1:6 andhigher. The gel content of these polymers is extremely low, especiallywith solution polymerization.

Nitrogen can be used as inert gas in the preparation of the catalystsand in the polymerization, this being a possibility which does not existwhen using metallic lithium as catalyst.

The danger of lowering the molecular weights with an excessive supply ofthe catalyst is also considerably reduced, especially when usingcatalysts containing highly dispersed substances of large surface area,since the maximum concentration of catalysts based on organic calciumcompounds is not nearly .as critical as with the hitherto knowncatalytically active alkali organo-metallic compounds.

When Z-methyl-butadiene is polymerized with the catalysts according tothe invention, it is possible inter alia to prepare polymers of whichthe monomer units, according to infra-red spectroscopic investigations,are more than 90 percent linked in the 1,4-cis-arrangement.

The polymers prepared in accordance with the present process can beworked by the conventional methods, inter alia to elastic products withgood elastic properties, that is to say, they can for example bevulcanized with addition of conventional vulcanizing agents, fillers,pigments, stabi- :lizers and age-resistors. The Z-methyhbutadienepolymers prepared in this way are of particular industrial significance,since they can be worked in known manner into vulcanizates which showthe advantageous properties of natural rubber, especially a lowhysteresis and a high degree of elasticity and tensile strength with alow degree of hardness.

The experiments set out below are carried out in the absence of air andmoisture in a nitrogen atmosphere, the parts indicated being parts byweight.

Example 1 Phenyl calcium iodide is prepared from 1.2 parts by weight ofcalcium and 4.08 parts by weighto'f phenyl iodide in absolute diethylether. On completion of the reaction, 128 parts. by Weight of lithiumbutyl are added and the mixture is stirred for 30 minutes at 25 C. The

' ether is then distilled off and replaced by benzene, so

that after the quantitative removal of the ether, 40 parts by volume ofa benzenic solution, dark red in colour, are

left, containing a small quantity of a light brown very finely dividedprecipitate.

3.2 parts by volume of the previously described catalyst solution aremixed with 150 parts by weight of 2- rnethyl-butadiene under a nitrogenatmosphere in an apparatus provided with a stirrer device, the saidbutadiene 1 having been carefully purified :beforehand by boiling overfinely divided sodium and subsequent distillation. The mixture is thenheated While stirring to 40 C. and the viscosity of the solution hasalready clearly increased after about 10 minutes. The polymerizationproceeds smoothly and is practically completed after four hours. 143parts by weight of a light brown viscous polymer are obtained. Thepolymer is thoroughly mixed in a kneader with 3 parts 'by weight ofstearic acid and 2.25 parts by weight of tris-(nonylphenyl)-phosphitewith the addition of 150 parts by weight of benzene, the polymer therebybecoming colourless. Drying takes place in vacuo at 50 C.

The intrinsic viscosity of the polymer is 6.87. 93% of the monomer unitsof the polymer are linked in 1,4-cisarrangement and 7% in a3,4-arrangement, this having been shown by the infra-red spectrum.

Example 2 2.44 parts by weight of phenyl calcium iodide in absolutediethyl ether are mixed by stirring with an ethereal solution of 0.84part by weight of lithium phenyl and 0.87 part by weight of lithiumbromide. After adding about 50 parts by volume of toluene, the ether isdistilled olf quantitatively, 2.8 parts by volume of the catalystsuspension which is thereby obtained and which is deep brown in colourare introduced into parts by weight of purified and dryZ-methyI-butad-iene and heated to 40 C. while stirring or shaking. Theviscosity of the solution has clearly increased after about 30 minutesand polymerisation is stopped after 5 hours. The tough solid mass whichis obtained is introduced into a solution of 5 parts by weight of aceticacid and 3 parts by weight of phenyl-B-naphthylamine in 500 parts byvolume of isopropanol. After 24 hours, the polymer is washed with coldwater on a washing roller and dried at 50 C. in vacuo. 96 parts byweight of polymer are obtained with an intrinsic viscosity of [1;]=5.92.87% of the monomer units of the poly-2-methyl Ibutadiene therebyobtained are linked in the 1,4-cis-structure and 13% in a 3,4-structure.

Example 3 3 parts by Weight of finely divided, aluminum oxide (afterdrying by strong heating) are mixed under. nitrogen with 20 parts byvolume of the catalyst solution obtained according to Example 1 andstirred for 1 hour at 30 C. 5 parts by volume of this light browncatalyst suspension are introduced into a mixture of 100 parts by weightof 2-methyl-butadiene and 200 parts by weight of cyclohexane and stirredat 50 C. Polymerization starts after about 15 minutes and is practicallycompleted after 6 hours. The viscous reaction product is mixed in akneader with 2 parts by weight of stearic acid and 2 parts by weight ofbis-(3-cyclohexyl-S-methyl-Z-oxyphenyl)-methane and thoroughly kneadedfor 1 hour. The solvent is then distilled off at a temperature of 40 C.under reduced pressure. 92 parts by weight of poly-2-methylbutadienewith an intrinsic viscosity of [)]]='6.43 are obtained.

Example 4 15 parts by volume of catalyst solution according to Example 1are stirred with a suspension of 2 parts by weight of active carbonblack in petroleum ether for 30 minutes at 40 C. 11.5 parts by volume ofthis catalyst suspension are heated with a mixture of parts by weight of2-methyl butadiene and 100 parts by weight of benzene to 50 C. Whilestirring or shaking. After 4 hours, the highly viscous mass isintroduced into a solution of 5 parts of stearic acid and 4 parts by,Weight of 9 N,N-diphenyl-p-phenylene diamine in 500 parts by volume ofethanol. The mixture is left standing overnight and is then washed withwater on a washing roller. After drying, there are obtained 142 parts byweight of polymer with an intrinsic viscosity of [1 ]=5.92.

Example Phenyl calcium iodide is prepared from 0.5 part by weight ofcalcium and 2.04 parts by weight of phenyl calcium iodide in diethylether, as described in Example 1. After reaction has taken place, 0.64part by weight of lithium butyl is added. The mixture is stirred for 30minutes at 25 C. and is then filtered with exclusion of air. Thefiltrate has 3 parts by weight of diphenyl ether added thereto, and thenthe diethyl ether is quantitatively removed under reduced pressure. Theresidue is washed with a little benzene and suspended in cyclohexane.2.5 parts by volume of the catalyst thus prepared are heated with 100parts by weight of 2-methyl-butadiene-1,3 for 6 hours and while stirringor shaking to 45 C. The solid polymerisation product, with addition of100 parts by weight of benzene, is intimately mixed in a 'kneader with 3parts by weight of stearic acid and 2 parts by weight oftris-(nonylphenyl)-phosphite. After drying, 93 parts by weight ofpoly-Z-methyl-butadiene are obtained, 90% of which are in a1,4-cis-structure and in a 3,4-structure. Example 6 6 parts by weight offinely powdered calcium chips, 0.5 part by weight of mercury chloride,40 parts of toluene and 18.5 parts by weight of zinc diethyl are heatedwhile stirring thoroughly for 5 hours to 120-125 C. Five parts by volumeof the catalyst suspension thus obtained and decanted off from unreactedcalcium metal are heated in a nitrogen atmosphere with 100 parts byweight of dried 2 met'hyl-ibutadiene-L3 to 60C. The polymerisation isstopped after 16 hours and the reaction product is worked up asdescribed in Example 1. 87 parts by weight of p0ly-2 methyl butadieneare obtained, the structure of which, as shown by the infra-redspectrum, has 87% of the monomer units in a 1,4-cis-bond and 13% in a3,4-bond.

Example 7 9 parts by weight of finely powdered calcium chips, 9 parts byweight of mercury diphenyl, 0.075 part by weight of iodine and 105 partsby weight of absolute diethyl ether are vigorously shaken under nitrogenin a flask with the addition of glass beads. After 4 days, the reactionmixture is filtered, 75 parts by weight of toluene are added and themain quantity of the diethyl ether is removed by distillation. 22.5parts by volume of the catalyst suspension thus prepared are introducedinto 150 parts by volume of purified 2-methylbutadiene-1,3 under argon.The polymerisation, which takes place at 50 C., is completed after about6 hours. 63 parts by weight of a solid, rubber-like polymer areobtained, 32% of which have a 3,4-structure.

The experiment is repeated with a catalyst which is carefully freed fromdiethyl ether residues. The 3,4-proportion of the polymer obtained inthis way is still only 8.9%.

Example 8 The catalyst is prepared by the procedure described in Example7, but the reaction is carried out in the presence of 12.75 parts byweight of sharply dried, finely powdered lithium bromide. Of the 75parts by volume of a reddishbrown catalyst suspension which is obtainedin this way, 12 parts by volume are introduced in an argon atmosphereinto a mixture of 100 parts by weight of Z-methyl-butadiene-1,3 and 300parts by weight of hexane. A highly viscous solution is formed onheating to 50 C. After 7 hours, excess isopropanol is added to thissolution, the polymer precipitating. 82 parts of polymer are obtained,this having an intrinsic viscosity of (7;) :82.

Example 9 A catalyst suspension obtained according to Example 1 isstirred with 2.5 parts by weight of triphenyl phosphine for 2 hours at50 C., is then cooled to 10 C. and filtered with suction. Thereddish-coloured precipitate is washed with a little methyl cyclohexane,dried under reduced pressure at 25 C. and finely dispersed in 30 partsby volume of benzene. 3.8 parts by volume of this dispersion are addedto a mixture of parts by weight of 2-methylbutadiene-1,3 and 70 parts byweight of cyclohexane and heated to 45 C. After 8 hours, the viscousreaction product is introduced into 500 parts by volume of an aqueousacetone solution containing 2% of phenyl-flnaphthylamine. After drying,64 par-ts by weight of a solid rubber-like polymer are obtained. Theultra-red spectrum shows that 91.5% of the monomer units are in a1,4-cis-bond and 8.5% thereof in a 3,4-bond.

Example 10 A polymer prepared according to Example 1 was processed to amixture of the following composition on a rolling mill:

Parts 1,4-cis-polyisoprene 100 Carbon black (inactive) 30 ZnO (active) 5Phenyl-a-naphthylamine 2 Paraffin 0.6 Activator (0.5v parts ofdibenzothiazyl-disulphide, 0.5 parts of diphenyl-guanidine) 0.7 Sulfur2.5

The product which was vulcanized in known manner had the followingproperties:

in Example 1 together with 1600 parts by volume of petrol ether (boilinglimits 40 to 60 C.) and 360 parts by weight of butadiene-1,3 areintroduced into a stirringtype autoclave under nitrogen and heated to 60C. Polymerisation is complete after 12 hours. The light brown viscouspolymer solution is mixed by means of a kneader with 5 parts by weightof phenyl-B-naphthyl amine and 3 parts by weight of stearic acid. Thepolymer solution which is now colorless is dried at 50 C. There areobtained 342 parts by weight of polybutadiene having an intrinsicviscosity of 2.3.

Example 12 5 parts by volume of the catalytic solution as described inExample 1 are introduced under nitrogen into a stirrertype vesselprovided with a reflux-cooler together with 70 ,parts by weight offreshly distilled 2-methylbutadiene-1,3 and 30 parts by weight offreshly distilled styrene and 100 parts by weight of petrol ether(boiling limits 30 to C.) and heated .to 60 C. Polymerisation startsafter about 10 minutes as can be noticed from the distinct increase inviscosity of the solution. Polymerisation is complete after- 6 hours.The polymer solution is mixed with 1.25 :parts of phenyl-B-naphthylamine and 2 parts by weight of stearic acid in a kneader. Aftersubsequent drying at 50 C. in vacuo there are obtained 91 parts byweight of a yellow coloured polymer having an intrinsic viscosity of3.9. The copolymer according to the UV- spectrum contains 28% ofstyrene. 92% of the isoprene units are in 1,4-boud.

Example 13 parts by volume of the catalytic suspension as described inExample 1 are introduced into a stirrer-type autoclave which has beenrinsed with nitrogen together with 100 parts by weight of petrol ether,50 parts by weight of butadiene-1,3 and 50 parts by weight of 2-methyl-butadiene-1,3. The reaction mixture is heated to 60 C. Afterhours the highly viscous polymer solution is let out of the autoclaveand mixed with 1.25 parts by weight of phenyl-fi-naphthyl amine and 3parts by weight of stearic acid. After drying at 50 C. there areobtained 93 parts by weight of a yellowish polymer having an intrinsicviscosity of 3.1.

Example 14 100 parts of hexane and 50 parts by weight of styrene areintroduced under argon into a pressure flask. By heating in a sand-bathpart of the solution medium is evaporated in order to remove remainingair. Thereafter 2 parts by volume of the catalytic suspension describedin Example 1 are added. Polymerisation is carried through at 50 C. After8 hours the reaction mixture is poured into ethanol. The resultinggreyishbrown coagulate is dissolved in xylene and precipitated byaddition of methanol. There are obtained 42 parts by weight of a purelywhite brittle polymer.

Example 15 200 parts by weight of petrol ether and 100 parts by weightof acrylic acid methyl ether are cooled to 45 C. in a glass-flask whichhas been freed from air and moisture by repeated evacuation and rinsingwith argon and which is provided with a stirrer. Thereafter 6 parts byvolume of a catalytic suspension according to Example 1 are addeddropwise. Polymerisation is interrupted after 12 hours. The reactionmixture is mixed with methanol. There are obtained 7 parts of arubber-like polymer.

The following examples nearer illustrate the preparation of the presentcatalysts.

Example 16 4.8 parts by weight of calcium chips are reacted in diethylether with 16.3 parts by weight of phenyl iodide. A solution of 5.12parts by weight of lithium butyl in cyclohexane is then added to thelight brown suspension. A deep reddish-brown solution is thereby formed,which can easily be separated from excess calcium. After adding toluene,first of all the ether and thereafter half of the added toluene aredistilled off under reduced pressure. Methyl cyclohexane isthen slowlyadded dropwise while stirring, a light brown precipitate being formed.This precipitate is suction-filtered, washed several times with methylcyclohex-ane and dried. The filtrate contains only traces of iodine andorganometallic compound. After drying in vacuo, 24 parts by weight of alight grey substance are obtained, and analysis of this shows a contentof 41% of iodine and 13% of calcium. The acid consumption in thehydrolysis is 6.48 parts by volume of normal hydrochloric acid for 1part by weight of substance. The compound is soluble in ethers, aromatichydrocarbons and tertiary amines. The compounds corresponds to theformula:

Li[ICa(C H (C H Example 17 An ethereal suspension of phenyl calciumiodide is prepared, as described in Example 1, from 4.8 parts by weightof calcium and 16.3 parts by weight of phenyl iodide, and an etherealsolution of 9.5 parts by weight of lithium phenyl and 9.2 par-ts byweight of lithium bromide is added thereto. The deep red solution isseparated from excess calcium, toluene is added while stirring, theprecipitate is suction filtered after a few hours and thereafter washedwith toluene. After drying, 13.2 parts by weight of a light brownsubstance which is readily soluble in ether is obtained, the substancecontaining 39% of iodine and 12.2% of calcium. 6.1 parts by volume ofnormal hydrochloric acid are used for 1 part by weight of substance inthe hydrolysis.

The compound corresponds to the formula:

Li s s) 2] The still reddish-coloured filtrate is concentrated andmethyl cyclohexane is added thereto until a precipitate is formed. Thisis suction-filtered and dried. Analysis shows 1.98 m.mol of calcium,9.95 m.mol of halogen and and acid consumption of 3.6 ml. of normalhydrochloric acid during hydrolysis of 1 part by weight of substance.The compound is soluble in ethers, tertiary amines and aromatichydrocarbons.

The compound corresponds to the formula:

Li [ICZl-(CgH5 Example 18 10 parts of calcium chips are reacted in partsof ether with 46 parts of n-butyl iodide. The mixture is stirred with anefficiently working sharp-edged steelstirrer. After the reaction hasstarted, the temperature should not rise above 30 to 35 C. Reaction iscomplete after 10 hours. The white precipitate formed during reactioncontains besides calcium iodide 22 parts of nbutyl calcium iodide.

After addition of parts of ether and 7.55 parts of lithium butyl, themixture is stirred at room temperature for one hour, the precipitatesucked off, the filtrate treated with toluene and the ether removed invacuo. By addition of methyl cyclohexane there can be obtained from thetoluene solution a light brown precipitate of the COIl'l', positionLi[ICa(C H which on precipitating from ether/n-hexane does not changeits composition and whichif left standing for some time-precipitatesfrom concentrated toluene solution in crystallized form.

Example 19 In order to obtain n-butyl calcium iodide the process ofExample 3 is carried through. After addition of 13.45 parts ofo-methoxy-phenyl lithium in 230 parts of ether the procedure isaccording to Example 3. The yellowbrown precipitate obtained from thetoluene solution by addition of methyl cyclohexane has--even afterrepeated precipitation-the composition Lillca (X6H4) s 4 a')] Example 204.8 parts .of calcium chips are treated with 16.3 parts of phenyl iodidein diethyl ether. By filtration and careful washing with ether thenon-precipitated metal and a small amount. of calcium iodide areseparated. The content of phenyl calcium iodide in the filtrate istitrimetrically determined and the filtrate treated with an equimolaramount of lithium dodecyl. After addition of toluene, ether is removedin vacuo at 10 C. After addition of n-hexane on cooling to 70 C. a lightbrown precipitate of the composition L [IC s 5) 12 25)] is obtainedwhich on recrystallizing from toluene or hexane does not change itscomposition.

We claim:

1. A calcium-containing catalyst compound of the.

formula:

n n I Z n] m wherein Me is a metal selected from the group consisting oflithium, sodium and potassium, R and R are selected from the groupconsisting of an alkyl having 4-- 12 carbon atoms, phenyl andphenoxymethyl, X is iodine, A is selected from the group consisting ofan alkali metal 13 halide and an alkaline earth metal halide, andwherein n is 1, and m is an integer from 0 to 3.

2. A calcium-containing catalyst compound of the formula:

Li[CaR R I] A 4. A calcium-containing catalyst compound of the formula:

Li[ G 5)2 5. A calcium-containing catalyst compound of the formula:

14 6. A calcium-containing catalyst compound of the formula:

7. A calcium-containing catalyst compound of the formula:

Li[Ca(C H I] -2LiBr 8. A calcium-containing catalyst compound of theformula:

References Cited by the Examiner FOREIGN PATENTS 821,107 9/1959 GreatBritain.

LEON ZITVER, Primary Examiner.

JOSEPH L. SCHOFER, Examiner.

20 C. R. REAP, B. HEL'FIIN, Assistant Examiners.

1. A CALCIUM-CONTAINING CATALYST COMPOUND OF THE FORMULA: